Electric railway-signal.



PATENTED MAR. 22, 1904.

B. M. KERSHNER. ELECTRIC RAILWAY SIGNAL.

APPLICATION TILED JUNE 21, 1902.

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FICSUIQE I INVENTOR.

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N0 MODEL.

FIGUDE E WITNESSES:

PATENTED MAR. 22, 1904. B. M. KERSHNER. ELEGTRIG' RAILWAY SIGNAL.

APPLICATION FILED JUNE 21, 1902. V

2 SHEETS-SHEET 2- IN VEN T OR.

ATTORNEY.

Patented March 22, 1904.

UNITED STATES PATENT OFFICE.

BERTRAM M. KERSH'NER, OF PITTSBURG, PENNSYLVANIA.

ELECTRIC RAILWAY-SIGNAL.

SPECIFICATION forming part of Letters Patent No. 755,140, dated March 22, 1904.

Application filed June 21,1902. Serial No. 112,559. (No model.)

To all whom it may concern:

form of my invention which I designate as the.

non-automatic form. Fig. 2 illustrates diagrammatically another form of my invention, which I designate the automatic form. Fig. 3 is a detail of the locking-magnet and the contacts operated thereby. Fig. 1 indicates the method of energizing the system by means of the motormans controller.

The object of my invention is to provide a system of signals for'railway purposes whereby the successive blocks into which the road is divided may be suitably protected against an entrance thereon of a car or train either following or in opposition to a car or train already on the block.

My system is particularly adapted for railways operated electrically, and it is illustrated herein in connection with a railway of that type, but it will be understood that it may be employed on any railway wherein a suitable line conductor, trolley contacts, and other' apparatus are provided.

In this system I have devised the following results are attained: First, a signaling device is set at the farther end of a block against cars or trains coming from that direction and signaling devices are likewise set at the near end of the block against following cars or trains; second, both of the above sets of signals are locked by the operating car or train, which may be called the master-car, since it is in control of the block and cannot be affected when once set by either an opposing or a following car or train, their release or clearing being solely under the control of the master car or train which set them; third, it is practically impossible for trains arriving at opposite ends of the blocks simultaneously to interfere with the proper setting of the signals; fourth, in the event of the supply-current being interrupted the restoration of the current acts to maintain the signals in the same condition that they were in previous to the interruption;

fifth, the signals may be both set and cleared without stopping or slowing up the speed of the car or train; sixth, the use of butone additional line-circuit is required, while the organization of the apparatus is simple in comparison with the results secured.

In the following description it will be understood that the term car includes any railway vehicle or train which may be employed upon the railway and that while I have shown electric lamps as the signaling devices they are but typical of signaling devices in general such as semaphores,indicators,bells,

or any other warning or communicating devlce, any of whlch may be employed inplaceof or in conjunction with the lamps. It will also be understood that the apparatus shown is but one of the many forms in which the invention may be embodied, it being the form which I regard at the present time as the best.

Referring to the drawings, I have shown as a characteristic situation for the embodiment of my invention a single-track trolley-road, in

trolley wire or conductor, (marked, respectively, S and S through the former of which the setting of the signals is accomplished and through the latter of which they are released or cleared. The corresponding sections for the adjacent blocks are indicated at s and 8 In the non-automatic arrangement shown in Fig. l the setting of the signals is under the control of the motorman and likewise their release, it being necessary for him when his trolley is passing over the sections S and S to maintain his controller closedfor example, on the first or second notchin order that he may thereby connect the section S to ground and so set the required signals, and in the same manner he may connect the section S to ground to clear or release them. The direction of the car is supposed to be from the left to right on the main line, as indicated by the arrows adjacent to the trolleywire T, while the car on the turnout is supposed to be going from right to left, as is also indicated by the arrows. It will also be understood that the master-car in setting the signal at the lefthand turnout causes a white light to be displayed and to remain burning behind it so long as it is on the block and a red light to be displayed ahead of it at the right-hand turnout, which will also remain burning so long as the car is on the block. Thus the white light will indicate to a following car that the block ahead is occupied by a car going in the same direction and a red light that the block is occupied by a car coming from the opposite direction,while the absence of any light at all will show that the block is clear.

The apparatus at one block is a duplicate of that at the next block and symmetrical therewith, so that they operate alike for both directions of travel.

In general I provide a signal-line parallel to the railway and about equal in length to the length of a block. At each end this lineis provided with a switch to connect it either to ground or to the feeder or other source of supply, and thereby bring it into a circuit including the lamps or signaling devices. At each apparatus there is a setting-magnet controlled by the car-trolley through the sections aforesaid and the car-controller, or through contact-plates adjacent to the trolley-wire and connected thereto by the trolley. There is also a locking device which prevents the switch being fully thrown at the far end of the block and which also disables both setting-magnets so that no other car can interfere with the signals after they are set by the master-car.

the restoring-magnet, which acts in opposition to the magnet A. The cores of these magnets are connected, respectively, to flexible straps W, which engage opposite sides of a lever pivoted in the standard P and provided with a switch-arm P operated thereby. Each arm P forms a terminal of the signaling-line X and in effect seeks to connect its corresponding end of the signaling-line either to the ground or the feeder. Normally when out of action both ends are connected to ground, though, if desired, both ends might be normally connected to the feeder and the switch then turned to ground to set the signals. The action of the restoring-magnet B throws the switch-arm into the position shown in full lines, with its extremity in contact with the terminal 5, leading to ground, while the action of the magnet A throws it over the center and allows it to fall into the position shown in dotted lines, with its extremity in contact with the terminal 6, leading to the feeder. A third magnet between the two aforesaid carries two coils C and D and operates the stop N and also the contact-lever E, which vibrates between the two terminals 0 O on the one hand and the terminals Z Z on the other, as shown in detail in Fig. 3. The coil C serves as a lockinginagnet,'its locking function in the form of my invention herein shown being performed by short-circuiting the setting-magnets at both ends of the block, so as to temporarily disable them or render them inoperative so long as the master-car is on the block. This prevents interference with the signals by a second car in either direction. It also controls and determines the action of the restoring-magnet B, while it is itself controlled by the clearing or releasing magnet of the apparatus at the opposite end of the block. The stop N somewhat overbalances the contactlever E and the core within the coils U and D, so as to occupy the position shown in Fig. 3 when no current is flowing in the coils. VVhe'n,

however, either of the coils is energized, the

stop N is thrown up against the switch-lever, so as toprevent its being thrown back beyond the central position, although still permitting it to be moved sufiiciently to allow its extremity to depart from the terminals 6 b and break the circuit. A white lamp L is connected between the terminal a and the feeder and a red light L is connected between the terminal 7/ and the ground.

The lower or setting section of the magnet A is connected on one side to the wire 2, leading to the trolley-section S, and on the other side to the wire 1, leading from the feeder F or from the trolley-wire T, if desired, or if no feeder isemployed to the other source of current. This setting-section is short-circuited and the apparatus thereby locked or disabled whenever the contact E descends into engagement with the terminals 0 O, connected, respectively, to opposite sides of the magnet by the wires 4: and 5. The upper or releasing section is connected on one side to the trolley-section S and on the other side to the aforesaid wire 1, and in multiple therewith is the coil D of the central magnet, its two wires 6 and 7 being connected to the opposite sides, respectively, of the releasingmagnet section. The coil D may be in series with instead of multiple with the releasingmagnet, if desired, it only being required that they shall act together, its function being to maintain the apparatus at the far end of the block against any departure from its normal condition when the release-magnet acts. In the corresponding apparatus at the right-hand end the releasing-section of magnet A is below and the setting-section is above; but this is immaterial, since in either relation they both act upon the core of the solenoid. If desired, the releasing-magnet can have a core of its own acting to break the main circuit, which is all that is required to clear the system. The signal-line X, joining thetwo devices at the opposite end of the block, comes in each case to the coil C of the central magnet, which may be termed the locking-coil, (its locking effect being due to the short-circuiting of the setting-coil, and passes thence by the wire 10 to the resistance Rand then to the switcharm P (which, as described above, may beconsidered as one terminal of the line) and from. the said arm to either feeder andthe white lamp or the ground and the red lamp, according to the position of the arm, while a branch circuit passes off below the resistance R to the coil B and thence to the terminals Z Z by the wire 9 and through the resistance R by the wire 8 to the red lamp L and then to the ground.

Assuming that the parts are in thecondition shown in Fig. 1, with no current in the apparatus, a car entering the block and going from left to right, as indicated by the arrow, will come to the trolley-section S, when if the motorman closes the circuit to ground through his controller current will flow through the setting-section of the magnet A, passing from the feeder F (or the trolley-wire T) by the wire 1 to the said magnet and thence by the wire 2 to the section S and to ground. This will throw the arm P from the position shown in full line to the position shown in dotted line, and thereby establish a connection through the signal-wire leading to thefarther end of the block, which will complete a circuit including the white lamp L at the near end of the block and the red lamp L at the farther end. The circuit will be as follows: Starting from the feeder F (or the trolley-wire T) by the wire 1 to the lamp L, to terminal I), to switch-arm P, to resistance R, by wire 10, to locking-magnet C, by the wire X, to the farther end of the block, where in like manner it passes through the locking-magnet O and resistance R to the switch-arm P, but thence itgoes to the red. lamp L since at that end of the block the arm P is still in contact with the terminal I). The condition of the apparatus at the farther end thus remains unchanged.

, by parting from the terminal 7).

From the lamps L the circuit goes to the ground G. At both stations there is a momentary branch current from the wire 10 through the magnet B,.wire 9, contacts Z Z, wire 8, resistance R, lamp L to ground; but this branch is immediately broken by the action of the locking-coil C, which draws down its core and breaks the contact of the lever E with the terminals Z Z and closes its contact with the terminals 0 O. This accomplishes two tl'iings: First, it throws the stop N up into position to prevent the movement of the arm P past the center, and, second, it shortcircuits the setting-section of coil A. This occurs at both stations and effectively prevents either the movement of the switch-arm P or the action of the setting-coil, so that no car, either behind or ahead of the master-car that is in control of the block, can interfere with the apparatus so long as the master-car is on the block. .Coming next to the clearing or releasing action, it is evident that it cannot occur until the master-car reaches the end of the block and strikes the section S of the trolley-wire. Then if the motorman closes his controller, as he should do, this trolley-section is grounded and the releasing-section of the magnet A at the end of the block is energized in just the same manner as the settingsection was energized at the beginning of the block-that is to say, the current from the feeder (or trolley-wire) passes to the wire 1 through the releasing magnet-coil (which acts upon the same core as the setting-magnet) to the wire 3, thence through the section S and the controller and motorof the car to ground. At the same time, however, a branch current passes through the wire 6 and 7, through the retaining-coil D of the same apparatus at the end of the block. The energized release-mag net draws up the switch-arm P and breaksits connection with the terminal 6, so as to break the above-described circuit of the signal-line and allow the apparatus at the beginning of the block to come back to its normal position by the action of the restoring-magnet B, which is momentarily energized by the dropping of the stop Nfthe rising of the core of the locking-magnet, and the closure of the circuit of the magnet B through the terminals Z Z. The current, which formerly passed from the feeder over the signal-wire- X, is thereby shunted to ground through magnet B, which immediately acts to throw over the arm P and at the same time to open its own circuit At the righthand apparatus, however, nothing more occurs, because the retaining-coil D there is energized, and so retains the stop N in a position to prevent the throwing over of the arm P by the release-magnet. This apparatus, therefore, remains in the same condition as it was before, which is its normal condition at all times when acting as the terminal apparatus of a block. Of course if the car were passing in the opposite direction the left-hand apparatus would then be the terminal apparatus and would in like manner be retained in its normal condition by the coil D. In that event, also, the right-hand apparatus would act to set the signal in the manner already described with respect to the left-hand appara tus, since the two devices are alike and symmetrical and operate for either direction of movement of the car.

Turning next to the automatic form of my invention shown in Fig. 2, the only difference between it and the form already described is that the trolley-wire remains unbroken by any insulated sections, and the trolley acts to set the signals by coming into engagement with a contact-plate V, and thereby delivering the current from the trolley-wire to the said plate, thence to the setting-section A of the first apparatus, and thence through the resistance R to ground. In like manner the clearing or release is effected by the engagement of the trolley-wheel with the contact-plate V and the resultant diversion of current through the releasing-section of magnet A and thence through the resistance R to ground. In this case no attention is required on the part of the motorman, who has no duty except to observe the signals, whereas with the non-automatic form he was also obliged to attend to the setting of the'signals by closing his controller when his trolley is on the section S and the release of the signals by closing his controller when the trolley is on the section 8*. Apart from this difference in the particular way of introducing the operating-current to the apparatus there is no change in the character or operation of the devices.

To provide for the restoration of the parts to the same condition after the temporary interruption of the current-supply, I so design the coils C C that they will act more quickly than the restoring-coils BB. Therefore when the power-current reappears after a temporary interruption the locking-magnets C C will catch and hold the apparatus at each end of the block before the restoring-magnet can act to throw the switch-arm P from the position it occupied previous to the interruption.

What I claim as new, and desire to secure by Letters Patent, is-

1. In a signaling system, the combination with a line-wire, of a vehicle provided with a traveling contact bearing upon said wire, a signaling-wire extending over one block or division of the road and normally grounded at each end, a switch for disconnecting one end of said signal-wire from the ground and connecting it to the source of current-suppl y, two magnets for operating the said switch, one connected to a contact for setting the signal and the other to a contact for restoring it, and means for controlling the latter magnet from the opposite end of the block over the said signal-wire.

2. In a signal system, the combination with a line-wire, of a vehicle provided with a contact device bearing thereon, a signal-wire extending over one block or division of the road, a switch at each end of said wire for connecting one end to the ground or to the source of current-supply, signaling devices in the circuit of which the said signal-wire forms a part, a setting-magnet for said switch connected with a contact at one end of the block, a restoring-magnet therefor controlled by the ins terruption of the signal-line, contacts for said restoring-magnets, amagnet in the signal-line operating said contacts, and means at the opposite end of the block for breaking the signal-line circuit, whereby the rupture of the signal-circuit at the leaving end of the block may cause the operation of the restoring mechanism at the entering end.

3. In a railway signal system, the combination with a signal-line extending along a block or section of the railway, of a dead-centered switch-arm at each end of the said line determining the connection of the line to the ground or to the source of the current-supply, signal devices operated by the current of said line, oppositely-acting magnets for each switch-arm to throw it on one side or the other of the dead-center, a retaining device for said arm and controlling-contacts for each magnet,

those for one magnet being controlled by a car entering the block and those for the other magnet controlled by the car leaving the block.

4:. In a signaling system, the combination with a line-wire of a vehicle provided with a contact device bearing thereon, a signal-wire extending over one block or section of the road, a switch at each end of said wire for controlling its connections with the ground or the source of current-supply, signaling devices adapted to be included. in the circuit of which the said signal-wire forms a part, a settingmagnet for the said switch, means for temporarily disabling or rendering the said magnet inoperative solong as a car is on the said block, a clearing magnet and a retaining device adapted to be operated at the farther end of the block to prevent the operation of the switch at that end of the signal-wire.

5. In a signaling system, the combination with a signal-Wire extending alonga block or division of the road, a switch at each end for controlling its connection with the ground or the source of supply, a setting device for the switch at the near end of the block, a restoring-magnet therefor at the same end and a clearing-magnet operated at the farther end of the block and controlling the said restoring-magnet.

6. In a signaling system, the combination. with a signal-wire extending over one block or division of the road, of a switch at each end for controlling its connection with the ground or the source of current-supply, signaling devices adapted to be included in the circuit of IIf which the said line-wire forms a part, asetting device for the switch at the near end of the block, a locking device controlled from the farther end of the block and a restoringmagnet controlled by the said locking device.

7. In a signaling system, the combination with a signal-wire extending over one block or division of the road, a switch at each end for connecting it either to the source of electric supply or the ground, a setting-magnet for said switch, a contact controlled by a passing vehicle for energizing the said setting-magnet, means for disabling or rendering the said setting device temporarily inoperative so long as a car is on the block, a locking device controlled from the opposite end of the block and a restoring-magnet controlled by the said locking device.

8. In a signaling system, the combination with asignal-wire extending over a block or division of the road, a switch at each end for connecting it either to ground or to the source of current-supply, signal devices adapted to be included by the action of one of said switches in a circuit of which the said signal-wire forms a part, a magnetic device controlling the switch and provided with two coils, one

a setting-coil and the other a clearing-coil,

contacts for each of said coils controlled respectively by cars entering and leaving a block,

means for disabling the setting-coil while a car is on the block, a locking device set by the setting-coil at the entrance end of a block and controlled by contacts at the leaving end operated by the clearing-coil at said leaving end, a restoring device, and a retaining-magnet at the farther end of the block energized simultaneously with the clearing-magnet.

9. Ina signaling system,-the combination with a signal-wire extending along a block or division of the road, a switch at each end of the line for connecting it either to the ground or the source of electric supply, a setting-magnet therefor operated by a contact controlled by a car at the beginning of the block, a clearing-magnet therefor at the end of the block controlled by a contact operated by the car, a locking-coil for each switch, contacts therefor controlled by the said setting-magnet, a restoring-magnet controlled by each of the said locking-magnets and a retaining-magnet at the end of the block for preventing the throwing over of the switch at that end.

10. In a signaling system, the combination with a signal-wire extending over one block or divisionof the road, a switch at each end for connecting 1t either with the ground or the source of electric supply, operating-magnets for the said switches and means for control ling the said magnets through the controller of an electrically-propelled vehicle on the railway.

- 11. In a signaling system, the combination with a signal-wire and electric signaling devices of a controlling-switch therefor, an operating-magnet connected to an insulated section of trolley-wire, an electrically-propelled vehicle and a controller for the propelling-motors thereof controlling also the said operating-magnet.

12. In a signaling system, the combination with a signal-wire extending along a block or division of the road, of electricsignaling devices operated thereby, signal-setting devices, retarded signal-restoring devices, locking devices and a magnet for said locking devices responding in advance of the restoring devices to a current admitted to the line when the apparatus is in a set condition.

13. In a signaling apparatus, the combina' tion with signal-setting devices, of a quick-acting locking magnet therefor in the mam l1ne and a slow-acting restoring-magnet controlled by the locking-magnet whereby the restoringmagnet is prevented from operating upon the return of the line-current after a temporary interruption.

14. In a signaling apparatus, the combination with a signalwire extending along a block or division of the road, signaling devices operated by the current in said signal-wire, automatic circuit-closers at each end of said signal-wire, a setting-magnet connected with the circuit-closer atthe beginning of a block and operating the same, a locking-magnet in the main line'controlling the setting-magnet and a slow-acting restoring-magnet controlled by the locking-magnet.

- In witness whereof I have hereunto set my hand, this 17th day of June, 1902, before two Witnesses:

WM. T. WALLACE, JNo. M. MILLIKIN. 

